Mice in Action: Small Gaps, Big Problems! In this video, you can see just how easily mice squeeze through tiny gaps. In this case, a small space between the soffit and brick of a home. These little intruders may seem harmless, but they can cause damage, contamination, and stress once inside. One way to track their activity? Mice leave behind a urine trail along their paths, it’s how they mark their routes and find their way back to food and shelter. If you notice droppings, gnaw marks, or greasy